RGO/N-porous carbon composites for enhanced CO2 capture and energy storage performances

Abstract

A novel porous carbon derived from glucose and dicyandiamide incorporated with reduced graphene oxide (rGO) was prepared for CO2 capture and supercapacitors. In this synthesis, one-pot hydrothermal and KOH activation were employed to obtain reducing graphene oxide/N-doped porous carbon (rGO/NPC) composites. Among the rGO/NPC composites derived, the sorbent rGO/NPC-600-2-1 (1 represents the addition amount of graphene oxide is 1% of the total mass of glucose and dicyandiamide, 2 represents the mass ratio of potassium hydroxide to the precursor of carbon composite material is 2 and 600 means activation temperature is 600 °C) had a large surface area of 865.1 m2 g−1, a rich nitrogen doping amount of 7.07 wt%, and a high CO2 capture ability of 5.77 mmol/g at 298 K. Additionally, the as-synthesized rGO/NPC-600-2-1 was used as a supercapacitor electrode, providing a specific capacitance 210.8 F g−1 in 6 M KOH electrolyte under ambient conditions and excellent charge and discharge long cycle stability (circa 100% capacitance retention at a current density of 10 A g−1 after 10000 cycles). Even at a high current density of 20 A g−1, a capacity of 141.1 F g-1 is still maintained. The results above suggested that the rGO/NPC composites are applicable candidates for both electrochemical energy storage and CO2 capture.